#include <iostream>
#include <string.h>
#include <algorithm>
using namespace std;
int main() {
  char str[101];
  cin >> str;
  int len = strlen(str); // for 0 -> len 
  // char init[101];
  // strcpy(init, str); // for 0 -> len
  // reverse(str, str + len); // for 0 -> len
  // // init == str;
  // // for 0 -> len
  // cout << (strcmp(init, str) == 0 ? "yes" : "no") << endl;
  bool diff = false;
  for (int i = 0, j = len - 1; i < j; i ++, j --) {
    if (str[i] != str[j]) {
      diff = true;
      break;
    }
  }
  cout << (diff ? "no" : "yes") << endl;
}